Preassembly of cooperating parts

ABSTRACT

A grommet is provided with an anchoring structure or structures for capturing a shrink wrap sleeve thereagainst, to inhibit the sleeve from sliding off the grommet. The anchoring structures are remote from an end surface of the grommet in an assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present regular United States Patent Application claims the benefitsof United States Provisional Application Ser. No. 60/724,359, filed Oct.6, 2005.

FIELD OF THE INVENTION

The present invention relates generally to the grouping, preassembly andfixation of adjacent cooperating parts that may not securely attach oneto another, for subsequent installation of the group as one subassemblyin an overall assembly.

BACKGROUND OF THE INVENTION

It is known to provide preassembled parts and subassemblies thatsubsequently are attached to other components to complete assemblies.For example, on assembly lines for automobiles, many differentpreassembled components are arranged and installed to complete theautomobile. Some preassemblies are complex having many parts attached toone another and ultimately installed in the final assembly.

Some systems of an automobile, for example, require many individualparts that are installed in succession, and which cooperated with oneanother but do not attach securely to each other until the finalassembly is complete. For example, in automobile suspension systems aconnection between a suspension arm and rod may include the rod passingthrough a hole in the arm with fasteners, washers, grommets, spacers andthe like on each side of the arm. The installation of each individualpiece during final assembly of the automobile can be complex and timeconsuming. If assembled in a wrong order, or with one part missing theassembly will not work correctly. Nuts, grommets, washers and the likecan be difficult to handle individually as discrete parts, slowing finalassembly.

To facilitate final assembly, it is known to group unconnected butadjacent parts together so that an entire group can be installed in asingle step. Grommets, nuts, washers and the like may engage each otherto some limited degree; however, handling can cause the parts to becomedislodged. When the preassembled group of parts is disrupted, the entiregroup is unusable unless a skilled assembler can properly position therandom parts.

Accordingly, it has been known to use shrink wrap surrounding thegrouped, pre-assembled parts to secure the relationships between theindividual parts in the group. The group is installed in the finalassembly with the shrink wrap in tact, and allowed to remain bundledwith the shrink wrap after assembly.

For example, in a known prior art group of parts for a vehiclesuspension, a grommet and a washer have been grouped alone, or with anut, spacer or the like, and held together by a shrink wrap sleeve ofknown material that is installed initially loosely over the parts andsubsequently treated, such as by heat, to shrink and fit snugly againstthe parts, securing the parts together. In a final assembly, a group ofa grommet and a washer with a shrink wrap sleeve in tact is placed on arod and against a shoulder. A suspension arm is positioned also on therod and against the group. Thereafter, a second group of a grommet awasher and a nut with its shrink wrap sleeve in tact is positionedagainst the arm, and the nut is rotated to engage threads on the rod tosecure the final assembly in proper position between the shoulder at oneend and the nut at the other end.

While groupings of parts such as that described above have workedsuccessfully and advantageously for efficient assembly, to ensure thatthe shrink wrap sleeves remain in position during handling andinstallation of the groups of parts so that the parts are not dislodgedand lost, the sleeves surround substantial portions of the grommets andother parts, including downwardly sloping ends thereof that come incontact with other parts in the final assembly. As a result, duringangular movement of a joint formed by the parts, as the parts move andtwist at various angles relative to each other, the shrink wrap sleevescan be pinched between opposed surfaces of the arm and grommets or otherparts initially held by the shrink wrapped sleeve. With continuedangular movement, continuous or intermittent rubbing of the shrink wrapsleeves between the parts can cause unacceptable noise, and even amistaken presumption of failing or improperly working parts. However,due to the smooth outer surface and shape of the grommet, if thedownward sloping surface of the grommet is not wrapped by the sleeve,the sleeve can slide off the grommet, resulting in the group becomingunusable.

Accordingly, it is desirable to provide a means for using shrink wrap tohold otherwise loose parts in proper sequence and position, withoutcausing subsequent interference with the cooperating parts.

SUMMARY OF THE INVENTION

The present invention provides shrink wrap retaining or anchoringfeatures on one or more of the parts, such as the grommet to provide ananchor against which the shrink wrap can constrict, with the anchors andshrink wrap positioned away from contact surfaces in the final assembly.

In one aspect thereof, the present invention provides a group of partswith at least a first part, a loosely associated second part and ashrink wrap sleeve encircling the parts. At least one of the parts hasat least one shrink wrap anchor in the form of an abrupt diametertransition on an outer surface against which the shrink wrap sleeve isconstricted for holding the first and second parts in position relativeto one another.

In another aspect thereof, the present invention provides a grommet witha grommet body having a first end, a second end and a substantiallysmooth outer surface. The first end is configured for engagement againstanother part in use. Shrink wrap anchors spaced from the first end areprovided for anchoring a shrink wrap sleeve remote from the first end.

In a still further aspect thereof, the present invention provides agrommet assembly with a grommet, a second part held against an end ofthe grommet and a shrink wrap sleeve encircling the grommet and thesecond part. The shrink wrap sleeve is constricted against the secondpart. At least one shrink wrap anchor is provided on the outer surfaceof the grommet, and forms an abrupt transition in diameter of thegrommet near the end of the grommet. The sleeve is constricted againstthe at least one sleeve anchor. An opposite end of the grommet isuncovered by the sleeve.

An advantage of the present invention is providing a structure whereby aminimal amount of shrink wrap can be used for holding otherwise looseparts together without enveloping the entire group of parts completely.

Another advantage of the present invention is providing structurewhereby shrink wrap can be used to group otherwise loose parts togetherwhereby the shrink wrap can be held away from surface areas of the partsthat are contact surfaces in a final assembly.

Still another advantage of the present invention is providing structurewhereby shrink wrap can be used to group otherwise loose parts andwhereby the shrink wrap can be removed easily after final assembly, ifdesired.

Other features and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims and drawings in which like numerals are used todesignate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a grouped assembly of parts inaccordance with the present invention;

FIG. 2 is an end view of the grommet assembly shown in FIG. 1;

FIG. 3 is an elevational view similar to that of FIG. 1, butillustrating a second embodiment of the present invention;

FIG. 4 is an end view similar to that of FIG. 2, but illustrating theembodiment of FIG. 3; and

FIG. 5 is an elevational view of an assembly having two groups of partsin accordance with the present invention.

Before the embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangements of the components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use herein of“including”, “comprising” and variations thereof is meant to encompassthe items listed thereafter and equivalents thereof, as well asadditional items and equivalents thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more specifically to the drawings and to FIG. 5 inparticular, an assembly 10 is shown having a first group of parts 12 anda second group of parts 14, each of the groups of parts 12 and 14 beingpreassembled in accordance with the present invention. Groups of parts12 and 14 are first and second grommet subassemblies mounted on a rod 16which also engages an arm 18, with groups 12 and 14 on opposite sides ofarm 18. As depicted, assembly 10 can be a portion of a vehiclesuspension system; however, it should be understood that the presentinvention can be used for groups of parts in other types of suspensionsystems, in automobile systems other than suspensions systems and forassemblies other than automobiles.

With reference now to FIG. 1, group 12 is shown. Group 12 is an outergrommet subassembly and includes a grommet 20 being a body having asubstantially smooth outer surface 22. A washer 24 and a nut 26 areprovided at one end of grommet 20. Nut 26 can be attached to washer 24or loosely associated therewith for rotation thereagainst. Nut 26 alsocan be connected to a spacer or sleeve-like extension 28 extendingthrough grommet 20. Grommet 20 is provided with a sloping first endsurface, generally designated by numeral 30, which is held against arm18 in assembly 10 and thereby is a contact surface of grommet 20 againstarm 18. As relative movement occurs between grommet 20 and arm 18, thearea of contact against end surface 30 changes. Grommet 20 has a secondend 32 opposite first end 30. Second end 32 is adjacent washer 24 andnut 26.

A sleeve 34 is provided to group and secure the associated parts ofgrommet 20, washer 24 and nut 26. Sleeve 34, designated by a line inFIG. 1, surrounds the associated parts, or at least a portion thereof,encircling washer 24 and the end portion of grommet 20 adjacent washer24. Sleeve 34 is a shrinkable film that can be applied loosely andthereafter shrunk to lie tightly along and over the surfaces it covers.Suitable shrinkable films are known for many uses and purposes. Uponactivation, such as by heat, the film constricts tightly. Since the filmconforms closely against even irregular surfaces, otherwise nonconnectedparts can be held together securely.

If shrink wrap substantially surrounds and envelopes things to be heldthereby, the shrink wrap remains in place securely. Relative movementbetween a shrink wrap package and a substantially smooth surface canoccur, particularly if the shrink wrap terminates on a major diameter ofthe smooth surfaced object.

Accordingly, in part groups such as group 12, it has been known toenvelope the grommet and the other parts, including substantially endface surfaces of the outer most parts, including end surface 30 ofgrommet 20, so that shrinkage of film 34 applies axial force against theoutermost parts to secure the relative positions of the parts withrespect to one another.

Grommet 20 is provided with an anchoring fixture or structure in theform of an annular ring 40 projecting outwardly from surface 22 remotefrom end surface 30. Ring 40 in the exemplary embodiment is nearer tosecond end 32 than to first end 30. Ring 40 defines an abrupt diametertransition on surface 22 against which the shrink wrap sleeve 34 canconstrict. In the exemplary embodiment, ring 40 defines an overall majoror largest diameter of grommet 20.

Sleeve 34 extends just beyond ring 40, only minimally toward end surface30. However, a terminal edge 42 of sleeve 34 is held securely inposition on grommet 20, being anchored by ring 40 against which sleeve34 constricts. Sleeve 34 is retained well away from portions of surface30 that contact arm 18 during angulations of the completed assembly.

Group 14 (FIG. 5) is similar to group 12, and similar components thereofare identified with the same numerals as the corresponding components ingroup 12. Essentially, group 14 includes a second grommet 20, a secondwasher 24 and a second shrink wrap sleeve 34 there around. However,being an inner grommet subassembly, second group 14 does not include anut 26.

FIGS. 3 and 4 illustrate a variation of the previously described grommet20. A grommet 50 has a substantially smooth outer surface 52 andincludes a plurality of dimples or bumps 54 arranged spaced from acurved end surface 56 of grommet 50 which is a contact surface againstarm 18 after installation. In FIGS. 3 and 4, four dimples 54 are shown,although more or fewer dimples 54 can be used. Dimples 54 serve asanchors for and cooperate with a shrink wrap sleeve 58 to retain sleeve58 on the group of parts, but with an edge 60 of sleeve 58 well awayfrom the portions of surface 56 that may contact arm 30 afterinstallation. Again, a terminal portion of sleeve 58 surrounds eachdimple 54 and is anchored there against to hold sleeve 58 securely ongrommet 50.

Grommets 20 and 50 have substantially smooth outer surfaces, 22 and 52,respectively, except for ring 40 and dimples 54 that project outwardlytherefrom as abrupt changes in diameter. The use of outward projectionsor anchors, such as dimples 54 or annular ring 40, allows the use ofshrink wrap sleeves 34, 58 that are of short axial length, and that areheld well away from the areas of end surfaces 30, 56 that may contactarm 18. Shrink wrap sleeves 34 and 58 are held away from and not locatedwhere the sleeves can be pinched between grommets 20, 50 and arm 18,thereby eliminating noise and mistaken interpretations of defectiveoperation from noise generated by pinching and rubbing against thesleeves.

It should be understood that a variety of shrink wrap retainingconfigurations other than dimples 54 and annular rings 22 can be used tosecure the positioning of the shrink wrap sleeve. Dimples 54 and annularrings 22 are merely two exemplary anchoring structures that createabrupt diameter transitions of increasing diameter. However, anchoringstructures defining abrupt diameter transitions also can be abruptlydecreased diameters. Accordingly, inward depressions or a channel alsocould be used to provide regions in which inward constriction of theshrink wrap can occur, thereby securing the shrink wrap in place andsecuring the group of parts. A plurality of discontinuous segments canbe used, rather than a continuous ring 40. Dimples of various shapes canbe used. The present invention can be used on outer parts of large partgroups as well as various intermediate parts within part groups. Theinvention can be used for large groups having many individual parts, aswell as on relatively small groups of parts as shown. While shown foruse with grommets and parts such as washers, nuts and spacers, thepresent invention can be used also for first and second looselyassociated parts of other types.

In assembly 10, rod 16 is inserted through second group 14, and washer24 abuts a shoulder (not shown) on rod 16 to limit further axialmovement thereon. Rod 16 is inserted through arm 18, and first group 12is then installed on rod 16, against the opposite side of arm 18 fromgroup 14. Nut 26 is rotated to engage a threaded end (not shown) of rod16. As can be seen clearly from the illustration of FIG. 5, sleeves 34are held well away from any pinch points that might occur between arm 18and grommets 20 and 50.

Variations and modifications of the foregoing are within the scope ofthe present invention. It is understood that the invention disclosed anddefined herein extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text and/ordrawings. All of these different combinations constitute variousalternative aspects of the present invention. The embodiments describedherein explain the best modes known for practicing the invention andwill enable others skilled in the art to utilize the invention. Theclaims are to be construed to include alternative embodiments to theextent permitted by the prior art.

Various features of the invention are set forth in the following claims.

1. A group of parts comprising: at least a first part and a looselyassociated second part; a shrink wrap sleeve encircling said parts; andat least one said part having at least one shrink wrap anchor in theform of an abrupt diameter transition on an outer surface against whichsaid shrink wrap sleeve is constricted for holding said first and secondparts in position relative to one another.
 2. The group of parts ofclaim 1, said shrink wrap anchor comprising an outwardly extending ringsurrounding one of said parts.
 3. The group of parts of claim 1, saidshrink wrap anchor comprising a plurality of outwardly projectingdimples on at least one said part.
 4. The group of parts of claim 1, onesaid part comprising a grommet, said grommet having an outwardlyprojecting ring surrounding said grommet, said ring comprising at leastone said shrink wrap anchor.
 5. The group of parts of claim 1, at leastone said part comprising a grommet, and said grommet having a pluralityof outwardly projecting dimples, and said dimples comprising shrink wrapanchors.
 6. The group of parts of claim 1, at least one said partcomprising a grommet, and said grommet having a substantially smoothouter surface and a projection on said outer surface defining an abruptdiameter transition, and said sleeve having a terminal edge near saidtransition.
 7. The group of parts of claim 6, said grommet having an endsurface, and said terminal edge of said the sleeve being disposed remotefrom said and surface.
 8. A grommet comprising: a grommet body having afirst end, a second end and a substantially smooth outer surface; saidfirst end configured for engagement against another part in use; and ashrink wrap anchor spaced from said first end for anchoring a shrinkwrap sleeve remote from said first end.
 9. The grommet of claim 8, saidshrink wrap anchor comprising an outwardly projecting ring surroundingsaid grommet.
 10. The grommet assembly of claim 8, said shrink wrapanchor comprising a plurality of outwardly projecting dimples.
 11. Thegrommet assembly of claim 8, said shrink wrap anchor comprising anabrupt diameter transition.
 12. The grommet assembly of claim 1, saidabrupt diameter transition being of abrupt increasing diameter.
 13. Agrommet assembly comprising: a grommet; a second part held against anend of said grommet; a shrink wrap sleeve encircling said grommet andsaid second part, said shrink wrap sleeve being constricted against saidsecond part; at least one shrink wrap anchor on an outer surface of saidgrommet, said anchor comprising an abrupt transition in diameter of saidgrommet near said end of said grommet, and said sleeve and beingconstricted against said at least one shrink wrap anchor; and anopposite end of said grommet being not covered by said sleeve.
 14. Thegrommet assembly of claim 13, said at least one shrink wrap anchorcomprising an outwardly extending ring surrounding said grommet.
 15. Thegrommet assembly of claim 13, said at least one shrink wrap anchorcomprising a plurality of outwardly projecting dimples on said grommet.16. The grommet assembly of claim 13, said abrupt transition being atransition of increasing diameter.
 17. The grommet assembly of claim 13,said at least one shrink wrap anchor being discontinuous.
 18. Thegrommet assembly of claim 13, said second part being one of a washer, aspacer and a nut.
 19. The grommet assembly of claim 18, said abrupttransition being a transition of increasing diameter.
 20. The grommetassembly of claim 13, said abrupt transition defining a major diameterof said grommet.